Pensions have become a pressure point for the campaign for Scottish independence, ever since chartered accountants' professional body ICAS reported in April that a Yes vote could open up a potential funding black hole.

That relates to EU laws on pensions and whether a vote for independence next September would trigger rules requiring all schemes operating across borders to be fully funded.

In a shift from Alex Salmond's earlier stated position, the SNP now admits this would be an issue, and a future Scottish Government would need to negotiate to delay the impact of these rules.

It could be possible to seek EU approval for existing long-term plans to address pension deficits, ministers claim. This may well be plausible.

The Better Together campaign argues that, without persuading 28 other EU countries of the need for Scotland to have a special deal, companies will be faced with a bill of billions of pounds to ensure cross-Border final-salary schemes are fully funded, post-independence.

The pro-Union campaign argues that some of these countries, notably the Czech Republic, which was recently fined for breaching the same rules, may be less than helpful. An Irish deal on UK/Irish cross-border pensions included only a three-year grace period.

But the overall thrust of the EU laws is to promote cross-border schemes, while ensuring they are safe, so this may be more than just wishful thinking by the Scottish Government. The Government's pensions plan also contains a guarantee to pensioners that anyone in receipt of the UK state pension at the time of independence will continue to have their pensions paid in full and on time.

That is not a surprising pledge, but what was more surprising was speculation suggesting that independence could see Scots receiving pensions earlier than people living south of the Border.

Deputy First Minister Nicola Sturgeon says she is not persuaded the UK Government timetable for raising the pension age to 67 is right or suitable for Scotland.

An expert commission is proposed, to review the timetable and the appropriateness of the change in the light of Scottish circumstances. But reversing the UK Government's decision to lift the retirement age could cost £6 billion according to some sources. The SNP appears reluctant to agree with this figure or to name its own.

Opponents lump the pledge along with plans including the proposal to renationalise Royal Mail and another to cut corporation tax and ask how this is all to be funded.

When promises are made about what the future will hold post-independence, people are entitled to ask how they will be paid for.

The Scottish Goverment should be able to explain how this can be affordable. Otherwise, suggesting pensions will be better - and paid sooner -appears to be a promise that can only be taken on trust.